It is common to store liquids, such as fuel, in portable containers for subsequent delivery into a destination container or the like. One example of such a portable container is a portable fuel container, made for carrying petroleum based products, such as fuel, and typically made from a petroleum resistant plastic material. Various types of these containers are well known in the prior art and are readily available. The destination container might be another portable fuel container, or the fuel tank of an apparatus having an external combustion engine, such as a vehicle, a boat, a lawn mower, and so on.
In many prior art portable fuel containers, a rigid nozzle or spout is securely attached thereto at an upper outlet. In order to deliver liquid from the portable container, the portable container is lifted and tilted, so the rigid nozzle or spout can be inserted into the inlet of the destination container, and liquid is poured from the spout into the destination container.
Some recently introduced portable containers have an fuel delivery hose attached to the portable fuel container at an outlet, with a nozzle and spout attached to the free end of the hose. An optional pump may be included in-line with the hose, nozzle and spout. In use, the spout is inserted into the inlet of the destination container, and liquid is delivered from the source container, namely the portable fuel container to the destination container, typically by means of siphoning or pumping.
One problem that exists with the use of such portable fuel containers is that vapour from the delivered liquid, especially liquid fuel, which evaporates quite readily, tends to escape from the destination container. In the case of transferring liquid fuel, this is highly undesirable. Indeed, it is believed that legislation exists, or is about to be enacted, in some jurisdictions, to require the recovery of vapour when delivering liquid fuel from a portable fuel container.
In a co-pending patent application by the same inventor, it is taught to have a flexible vapor recovery hose connected to the source container in addition to a flexible liquid delivery hose. The flexible vapor recovery hose is connected at its proximal end to the source container so as to be in fluid communication with the interior of the container. The distal end of the flexible vapor recovery hose either terminates adjacent the outlet end of the liquid delivery hose, the nozzle's spout, or may attach in vapor receiving relation to a separate vapor flow channel of the spout, which has its intake adjacent the liquid outlet end of the spout. Vapor recovery is accomplished by means of the reduced air pressure in the substantially hollow interior of the portable fuel container, which results from the removal of the liquid from the substantially hollow interior of the portable fuel container. This reduced air pressure causes vapor to be suctioned via the elongate flexible vapor recovery hose into the substantially hollow interior of the portable fuel container.
The problem with this method of vapor recovery is that there can be a significant delay in the start of the vapor recovery process. With volatile chemicals, such as liquid fuel, pressure can build up within the source container due to a higher atmospheric temperature or a decreased atmospheric pressure. This increased pressure within the source container would need to be relieved before the vapor would begin to be suctioned into the portable fuel container. Additionally, there is a head pressure associated with the amount of fuel within the container that will also need to be overcome before vapor would be suctioned into the portable fuel container.
In this hose system for fuel delivery and vapor recovery, the vapor recovery will only begin to occur at the point where the pressure within the container is relieved and the negative pressure within the container becomes low enough to overcome the head pressure of the liquid within the container, which means some of the environmentally harmful vapor displaced in the receiving fuel tank would not be recovered and would be released into the atmosphere.
Currently, there are some prior art fuel containers that accomplish vapor recovery in the above described manner, utilizing a standard spout. These containers have only one opening through which the liquid fuel flows out and through which the vapor flows back into the container. In these instances, the same spout is used to deliver liquid fuel and to recover the displaced vapor. These systems have the same shortcoming as the hosing system mentioned above in that there can be a significant delay in time between the fuel flowing out of the container and the vapor being drawn into the container, depending on the pressure and volume of liquid within the container.
U.S. Pat. No. 6,899,149 issued May 31, 2005 to Hartsell Jr., et al, discloses a Vapor Recovery Fuel Dispenser for Multiple Hoses. This dispenser is for dispensing volatile liquids such as hydrocarbon fuel for vehicles into a tank having a filler neck. It also collects the vapors generated by the dispensing to reduce atmospheric pollution. A fuel delivery hose includes a hand-held fuel valve and nozzle for insertion in the filler neck of a fuel tank or the like. An in-ground pump delivers fuel under pressure to the fuel delivery hose. A flow meter provides electrical pulses corresponding to the volumetric flow of liquid through the fuel delivery hose when the fuel valve is open. A micro-processor produces the signal applied to the vapor motor in response to the electrical pulses resulting from the flow of liquid to produce a volumetric flow of vapor corresponding to the volumetric flow of fuel to the tank. A vapor recovery hose includes a vapor intake connected to the hand-held nozzle for insertion in the filler neck of a fuel tank or the like. A separate above-ground motor-driven vapor pump produces a volumetric flow through the vapor recovery hose corresponding to the signal produced by the micro-processor and applied to the motor. The system as described in U.S. Pat. No. 6,899,149 has a number of drawbacks associated with it. Primarily, it is not portable and it is not manually powered. It is also expensive to manufacture and install. The dispensing system also absolutely requires electricity to operate, no matter what configuration of it might be used. Further, it is complicated in terms of its functionality. It relies on feedback from measurements of the flow of the fuel being pumped to cause vapor to be pumped. Accordingly, the pumping of the vapor could be significantly different than the pumping of the fuel, such as in situations where the interaction between the fuel flow measuring device and the fuel is not as expected.
It is an object of the present invention to provide a portable fluid exchange system for concurrently pumping liquid from a source container to a destination container and pumping vapor from said destination container to said source container.
It is an object of the present invention to provide a portable fluid exchange system for concurrently pumping liquid from a source container to a destination container and pumping vapor from said destination container to said source container, wherein the portable fluid exchange system can be manually powered.
It is an object of the present invention to provide a portable fluid exchange system for concurrently pumping liquid from a source container to a destination container and pumping vapor from said destination container to said source container, wherein the portable fluid exchange system is inexpensive to manufacture.
It is a further object of the present invention to provide a portable fluid exchange system that also suctions vapor displaced by the liquid, wherein the portable fluid exchange system does not need to be powered by electricity.
It is a further object of the present invention to provide a portable fluid exchange system that also suctions vapor displaced by the liquid, wherein the portable fluid exchange system is simple and uncomplicated.
It is a further object of the present invention to provide a portable fluid exchange system that also suctions vapor displaced by the liquid, wherein the portable fluid exchange system does not require feedback in order to operate.
It is a further object of the present invention to provide a portable fluid exchange system that also suctions vapor displaced by the liquid, wherein the pumping of vapor does not rely on certain conditions of the liquid flow to exist and be measured.
It is a further object of the present invention to provide a portable fluid exchange system that also suctions vapor displaced by the liquid, wherein the recovery of vapor is not dependent on the negative pressure within the portable fuel container.
It is a further object of the present invention to provide a portable fluid exchange system that also suctions vapor displaced by the liquid, wherein there is no significant delay in time between the fuel flowing out of the portable fuel container and the vapor being recovered into the container.
It is a further object of the present invention to provide a portable fluid exchange system that also suctions vapor displaced by the liquid, wherein the portable fluid exchange system is manually transportable by a single individual.